Regenerative telegraph repeater



April 18, 1939.

F, S. KINKEAD RE GENERAT I VE TELEGRAPH REPEATER Filed July 16, 1937INVENTOR ATTORNEY Patented Apr. 18, 1939 v UNITED STATES PATENT OFFICEREGENERATIVE TELEGRAPH REPEATER Application July 16, 1937, Serial No.153,878

10 Claims. (01. 175-320) This invention. relates to regenerativetelegraph repeaters of the start-stop type and more especially to thetiming means associated with repeaters of this type. The invention isparticularly related to improvements in timing means of the relay type.

In repeaters of this type, vibrating relay circuits are used as timingmeans in lieu of rotating distributors. One vibrating relay circuit istimed 1 to vibrate once for each impulse of a start-stop signal series,and another relay is timed to vibrate once only for each start-stopseries to stop the fast relay circuit at the end of each series. Acircuit of this type has been disclosed in United 15 States Patent1,771,445, issued to Parker-Vemam on July 29, 1930.

It is an object of the invention to provide 2. vibrating relay circuitcapable of producing short distinct impulses, of definite length andaccugo rately spaced apart.

In accordance with the invention, an unsymmetrical vibrating relaycircuit is provided which uses a polar relay in combination with acondenser, the armature of the relay being connected ,5 to a singlepolarity of potential for control of the oscillations.

In accordance with a further feature of the invention, the relay ispermanently biased in one direction, say, toward spacing, and has anoper- 30 ating winding for operation in the other direction, say, towardmarking.

In accordance with a further feature, the operating winding is fullyenergized, say, in spacing position, and quickly interrupts itself byoperating the armature to marking position, whereupon a condenser, incharging, continues the operating current for a time, ultimatelypermitting the biasing means to again operate the relay to spacingposition. These operations will then be rea peated at regular intervals.One or the other of the relay contacts is connected to an output circuitfor producing accurately timed impulses.

In accordance with another feature of the invention, the repeatercircuit includes additional .5 relay means for starting and stopping thetiming circuit for each signal series.

The invention will now be described in connection with a specificembodiment comprising a telegraph repeating system such as isillustrated so in the accompanying drawing, to which reference will bemade in the following description.

A number of arrows have been applied to the various relay windings inthe drawing to make understanding of the operations easier. The ar- 66rows which are drawn in full lines indicate the direction in which theparticular winding tends to operate the relay armature under theparticular circuit conditions shown in the drawing, whereas the arrowsshown in dotted lines indicate the direction in which the winding willoperate 5 the armature under alternate conditions. A double arrowindicates that the winding is more strongly energized than theassociated winding marked with a single arrow and thus indicates thatthe former winding is capable of preventing operation of the relay bythe latter winding.

The regenerative repeating system is shown connected between an incomingline circuit LW and an outgoing line circuit LE. Signals incoming overthe line west LW operate the receiving relay III which operates theretransmitting relay I I which in turn operates the line relay I2; linerelay I2 impresses the repeated signals upon the line east LE.

In this specific embodiment the receiving relay It has a permanentbiasing winding and has an operating winding responsive to opening andclosing of the line west. The line relay I2 transmits signals into theline east by opening and closing the line. The sources of current areassumed to 95 be located at the distant end of both line circuits. H Incase it should be desired to retransmit the signals into line east aspolar signals, relay I2 may be omitted and one line conductor of theline east connected to the armature of retransmitting 3U relay II.

The timing circuit comprises the elementary timing relay 20 and thecharacter timing relay 30. Relay 20 normally connects ground through itsmarking contact to short-circuit the operating windings of relay I I,thereby preventing response by relay II to operations of relay I0.During signaling, relay 20 oscillates in synchronism with signalsincoming over line west. For a short interval during each oscillationrelay 20 operates to spacing, thereby removing the short circuit forrelay II and permitting this relay to respond either to marking orspacing potential at relay IIl. After relay II has assumed its positionits winding is again short-circuited and the shortcircuiting currenttends to hold the relay in position without chattering. The relay I Imay be of a type which has sufiicient remanent magnetism to normallyhold the relay firmly against its contacts in either position; however,if desired, one of the operating windings may be disconnected from theoperating circuit and connected through a suitable resistance to thearmature of the relay for the purpose of self-locking in both positions,

asiswellknown. m

For the purpose of controlling the timing circuits a set of startingrelays 40 and 4| are provided. In their normal position these relaysapply ground to the operating windings of the timing relays 29 and 36,respectively, thereby locking the latter relays in their markingposition and preventing them from oscillating. When the receiving relayID, in response to a start impulse, operates to spacing, relays 40 and4| operate to spacing, thereby opening the locking circuits for relays2i] and 33. In spacing position, relay 40 short-circuits the operatingwindings of relays 49 and 4| which remain in spacing position inresponse to suitable biasing means, such as a light spring attached tothe armature.

Relays 2D and 30 then commence their cyclic operations, relay 20 with afrequency such that it will complete a cycle once for each incomingimpulse of a signal series representing a character, and relay 30 witha. frequency such that it will complete one cycle in a period slightlyshorter than the duration of a complete signal series.

The timing relay 2D has fixed biasing means, such as a biasing winding,continuously energized and tending to operate the armature to spacing.The upper operating winding is normally energized over the markingcontact of relay 40; the condenser 25 and resistance 26 areshort-circuited in this circuit. When relay 40 opens its markingcontact, the condenser 25 gradually becomes charged through theoperating winding of relay 2B and thus for a time serves to hold thisrelay to marking. When the charging current has decreased sufficiently,the biasing winding will overcome the operating winding and operate thearmature to spacing. At this moment ground at the spacing contact isapplied to this circuit. the condenser will be quickly discharged andfull operating current will be restored in the operating winding and therelay will quickly operate to marking, again permitting condenser 25 tobecome charged through the operating winding. Under these conditions thearmature of relay 20 will continue to oscillate and will be in itsspacing position for only a small fraction of its cycle thus producinghighly biased impulses by its contacts. By proper adjustment ofresistance 21 this fraction can be varied and by proper adjustment ofcondenser 25 and resistance 26 the frequency can be adjusted to coincidewith the impulse frequency of the signals.

The orienting resistance 28, in causing a. certain potential to beapplied to condenser 25, serves to normally establish a certain chargeon condenser 25 so that the first operation to spacing by relay 20 willtake place after a given interval upon opening of the marking contact ofrelay 4!] or in other words, upon the arrival of a start impulse overline west. By proper adjustment of resistance 28 the short spacingperiods of relay 20 may thus be oriented with respect to incomingsignals in such a manner that relay M will be permitted to respond torelay Ill only during that part of each incoming impulse which has leastdistortion,

Timing relay 30 also has a permanent biasing and its operating windingis normally energized over the marking contact of relay 4|; condenser 35and resistance 36 are normally short-circuited in this circuit. Whenrelay 4| responds to a start impulse, condenser 35 begins to chargethrough the operating winding of relay 30, thereby holding the relay tomarking. Condenser 35 and resistances 36 and 31 may be so adjusted thatthe operating current will not be sufflciently reduced to permit thebiasing winding to operate the armature to spacing until about the timethe last character impulse has been completed and the stop impulsecommences. At this time relay 30 goes to spacing and completes a circuitfrom the armature of relay H to the lower winding of relay 40. If atthis time relay happens tube in spacing position relay 4!] will be heldin spacing position. However, if relay II should be in marking positionrelay 4|] will be operated to marking and will stop the cyclicoperations of relay 2!]. Relay being in marking position, relay I0 mustalso be in marking position at this time, so that, when relay 40operates to marking, relay 4| will be operated to marking and will stopthe oscillations of relay 30.

Assuming the arrival of a start-stop signal series over the line west,the operations of the system will be as follows:

Line west and line east normally carry current and all the relays willnormally be in the positions shown in the drawing. When a start impulsearrives, line west will be currentless and relay l0 operates to spacing,closing a circuit from battery at its spacing contact through the upperwindings of relays 40 and 4|, thereby operating these relays to spacing;these windings will now be short-circuited at the spacing contact ofrelay 4D and the armatures will be held to spacing by the biasingsprings.

When the marking contact of relay 40 opens, condenser 25 begins tocharge through the upper operating winding of relay 20; similarly whenthe marking contact of relay 4| opens, condenser 35 begins to chargethrough the upper operating winding of relay 30. Due to the orientingadjustment of resistance 28 condenser 25 already had a certain charge,so that, after a compara tively short time, the charging current will bereduced to a Value at which the biasing winding will operate relay 20 tospacing. This will occur shortly before the arrival of the peak orcenter of the start impulse, at which time relay I is firmly positionedin response thereto. When relay 20 goes to spacing the short circuit atits marking contact is removed from the windings of relay H which now isgiven a short interval in which to respond to the position of relay I0and operate to spacing. Immediately after the passing of the peak of thestart impulse, relay 20 will return to its marking position, therebyefi'ectively preventing relay H from being disturbed by the nextoperation of relay I0. Relay 20, as previously explained, receives fulloperating current in spacing position and, depending upon the value ofresistance 21, is quickly returned to marking where it will be held bythe charging current from condenser 25.

Relay II in its spacing position causes relay 2 to operate to spacingand thus to send a. start,

relay In just at the time when relay I0 can be expected to be firmly inposition. Relay I operates relay l2 correspondingly and a correspondingcharacter impulse will be impressed upon line east.

For each of the five character impulses of the signal series theoperations will be repeated as just described ior the first characterimpulse.

The last impulse, or stop impulse, of each signal series being a markingimpulse, it is evident that in those instances where the last, or fifth,character impulse is also a marking impulse, all the transmission relaysI0, II and I2 will perform no transition between these two impulses, sothat it will be necessary only to time the operations in response to thefifth impulse. This fact is taken advantage of to provide a greatermargin for the restoration of relay 30 to marking position near the endof a signaling series, thereby requiring less accuracy in the adjustmentof relay 30.

Relay 30 has been held to marking by charging current from condenseruntil some time after the timing operation of relay 20 in connectionwith the fifth character impulse; at this moment the charging current issufficiently reduced to permit the biasing winding to operate relay 30to spacing. If at this moment relay II is in marking position, whetherthis be due to the filth character impulse or to the stop impulse,negative battery will be applied over the marking contact of relay IIand spacing contact of relay 30 through the lower winding of relaytooperate relay 40 to its marking position. Relay 40 now stops theoscillations of relay 20 so that relay I I will be prevented fromoperating until the next start impulse has been received over line west.The marking potential at relay I0 now operates relay 4| to marking,which in turn causes relay 30 to return to marking, thereby restoringthe circuit to normal in readiness for reception. of the next startimpulse.

However, if at the time relay 30 was ready for operation to spacingtransmitting relay II had been in spacing position due to the receptionoi. the fifth character impulse as a spacing impulse, spacing potentialwould have been applied over the contacts of relays II and 30 to thelower winding of relay 40, thereby holding relay 4!! in spacingposition.

When now the stop impulse arrives over line west to operate relay ill tomarking, relay 20 will perform its cyclic operation in the same manneras in timing the preceding impulses of this series, and relay II will beallotted a short interval in which to respond to the position of relayI0 and operate to marking, whereupon relay 20 returns to markingposition commencing a new cycle. Relay II operates relay l2 and the stopimpulse is transmitted over line east.

Relay I I now being in marking position, it will apply marking potentialover the spacing contacts of relay 30 to the lower winding of relay 40which operates and prevents further operations of relay 20. Relay I0being in marking position, relay 4| will be restoredto marking and willin turn operate relay 30 to marking, thereby reconditioning the circuitfor the next signal series.

Reference is made to my application for United States Patent, Serial No.153,879, filed on even date herewith and relating to the samesubjectmatter as the present application.

What is claimed is:

l. A timing circuit comprising relay means having contact means, anoperating winding and continuous biasing means, and capacitance meansconnected to be slowly charged through said winding and to be quicklydischarged over said contact means when the charging current issufilciently reduced for the operating winding to be overcome by saidbiasing means for operation of said contact means, and said operatingwinding being energized over said operated contact means to overcomesaid biasing means and restore said contact means.

2. An impulse producing relay circuit comprising a polar relay havingsubstantially constant biasing means for operating said relay to oneposition and having a series operating circuit including inductance andcapacitance for operation of said relay to its other position and havingcontact means including contacts connected to said operating circuit forperiodically controlling the charging and discharging current throughsaid capacitance means, said contact means being connected to producehighly biased impulses in an output circuit.

3. A polar relay having continuous biasing means for operating saidrelay into one position, a self-interrupting series circuit includingcontact means and an operating winding of said relay and a source ofunidirectional current for operating said relay into the other position,capacitance means bridged across said contact means to become dischargedin said one position and to become charged in said other position tohold said relay in said other position until the charging current hasdiminished to a predetermined value to permit operation of said relay bysaid biasing means.

4. An oscillating system as defined by claim 3 further comprising abridge circuit across said capacitance means including resistance meansand starting contact means adapted to complete in normal position saidbridge circuit to maintain a holding current in said operating windingand to maintain a limited charge on said capacitance means and to openin the other position said bridge circuit to permit oscillation of saidsystem, said resistance means being adjustable to vary the periodbetween the operation of said starting contact means from normalposition and the first operation of said system.

5. An unsymmetrical timing circuit for producing highly biased impulsesin an output circuit which comprises a polar relay having contact means,having substantially constant biasing means for operating said relayinto one position and having an operating winding for operating saidrelay into the other position; a series circuit including capacitancemeans, a source of unidirectional current and said winding for holdingsaid relay in said other position during the greater part of thecharging period of said capacitance means; said contact means beingconnected to bridge, in said first position, said capacitance means toquickly restore said relay to said other position.

6. A self-interrupted relay circuit for producing highly biased impulsescomprising a polar relay having continuous biasing means for operatingthe relay into one position, having contact means, and having a windingconnected through coming said biasing means to open said contact means;said start relay means having contact means connected through said startcircuit to said winding means to normally hold said first contact meansopen and to open said start circuit in response to an incoming startimpulse; said capacitance means being connected to be charged throughsaid operating winding means for holding said first contact means openwhen the charging current is heavy; and said first contact means beingconnected to close a discharge circuit for said capacitance means and toclose a circuit for said operating winding means, for quick reopening ofsaid discharge circuit.

8. An impulse producing relay circuit comprising a capacitance circuit,and a polar relay having a winding for operating said relay in onedirection, having contacts connected in circuit with said winding andhaving biasing means for constantly biasing said relay in the oppositedirection to close said contacts for energizing said windingcharacterized in this that said capacitance circuit is connected to becharged through said winding to temporarily hold said relay in said oneposition.

9. An impulse producing relay circuit comprising a capacitance circuit,and a polar relay having a winding for operating said relay in onedirection, having contacts connected in circuit with said winding andhaving biasing means for constantly biasing said relay in the oppositedirection to close said contacts for energizing said windingcharacterized in this that said capacitance circuit and said winding areserially included in a permanently closed circuit for charging saidcapacitance circuit through said winding to temporarily hold said relayin said one position.

10. An impulse producing relay circuit comprising a capacitance circuit,and a polar relay having a winding for operating said relay in onedirection, having contacts connected in circuit with said winding andhaving biasing means for constantly biasing said relay in the oppositedirection to close said contacts for energizing said windingcharacterized in this that said capacitance circuit and said winding areserially included in a permanently closed circuit for charging saidcapacitance circuit through said winding to temporarily hold said relayin said one position and that said contacts furthermore are connectedfor discharging said capacitance circuit when closed for energizing saidwinding.

FULLERTON S. KINKEAD.

